Heat olive oil over medium heat in a pan with a tight lid. Stir in onion and cook until onion is slightly translucent, about 5 to 7 minutes. Add in diced sweet potatoes and stir to coat evenly. Add 1/2 cup of water and cover. Let sweet potatoes steam about 10 to 15 minutes until tender. Remove cover and add cumin, smoked paprika, black beans and corn. Stir together to mix well. Then remove sweet potatoes mixture from heat.
Heat oven to 375°F.
In a 2-quart baking dish (I used a 10”x 7” dish), place a single layer of tortillas on the bottom. Spoon a layer of sweet potatoes, beans, and corn mixture. Cover with a few tablespoons of chimichurri sauce. Sprinkle with cheese mix. Continue to layer tortillas, vegetables, chimichurri, and cheese. Top off the enchilada casserole with a final layer of tortillas, chimichurri and cheese.
Bake 25 to 30 minutes until heated through and cheese is melted and slightly browning.
Remove from oven. Serve immediately with sliced avocado, pickled onions, cilantro, and more chimichurri.
While perusing the internet, I saw a brilliant trick from Cookie and Kate and love the idea of cutting the tortillas to get a good edge on the tortilla layer. If you’re using a different sized baking dish, you may need more or fewer tortillas. It’s also helpful to quarter them to get an even layer. I keep my skins on my sweet potato and dice them small so they cook quickly and match the size of the beans and the corn. This enchilada casserole is also excellent for freezing! Make a double batch in two casserole dishes and freeze up to 1 month. (I used disposable aluminum dishes to bring to friends.)
Omit the cheeses in this recipe. You need no substitute because you won’t miss the flavor! However, if desired, you can use a vegan cheese such as Daiya.
It would be easy to add ground meat to this enchilada casserole. I recommend a half pound, cooked and browned with the sweet potatoes. Ground turkey or chorizo would be an excellent choice. Or serve chicken grilled or fajita style on the side to accommodate different eaters.
I love the tres hermanas style combination of the corn, sweet potatoes, and black beans. However, you can swap pinto beans or regular potatoes if you have those ingredients on hand. In the summertime, bell peppers can be a nice addition in the enchilada casserole.
If you’ve never had pickled onions, they’re my new favorite condiment. I loosely follow this pickled onion recipe from Bon Appetit with one modification. I pour boiling water over the onions (through a strainer) before letting them sit in the vinegar. You can make your own beans on the stovetop or in a slow cooker instead of using canned beans.